1. Field of the Invention
The present invention relates to an image pickup apparatus, a white balance adjustment method therefor, and a program for implementing the method, and more particularly to an image pickup apparatus that can carry out bounce flash photography, and a white balance adjustment method therefor, and a program for implementing the method.
2. Description of the Related Art
Conventionally, to carry out white balance adjustment of a digital still camera, a TTL (through-the-lens) system has been frequently used. In the TTL system, light that has entered from the camera lens is photoelectrically converted by an image pickup device at the time of shooting, data roughly indicative of an achromatic color is extracted from image data obtained by the photoelectrically converted light, and R component and B component gains are calculated to convert the data into achromatic color data.
However, when this TTL system is used for shooting with electronic flash, various colors close to the color of the light source are contained in large amounts in the light from the object or no achromatic color is contained in the light, white balance adjustment is incorrectly carried out such that the color of the object becomes achromatic, for example.
To reduce such incorrect white balance adjustment even a little when electronic flash photography is carried out, achromatic color data is not extracted from image data obtained by photoelectrical conversion by the image pickup device at the time of shooting, but instead white balance adjustment is carried out using a white balance correction value corresponding to the light intensity of the electronic flash light (see Japanese Patent Publication (Kokoku) No. H08-17498, for example).
When this method is used, comparatively good white balance adjustment can be carried out if the electronic flash light is emitted directly onto the object.
However, at the time of electronic flash shooting, if bounce flash photography is carried out where the electronic flash irradiates light toward a white wall, for example, so that the light is indirectly irradiated onto the object, the light incident on the camera lens contains colors close to the color of light from the external light source which originally illuminated the object, in larger amounts than the color of the light from the electronic flash. Consequently, correction cannot be carried out correctly when white balance adjustment is performed using an electronic flash white balance correction value.